//  Copyright 2019 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

package paramhelper

import (
	"strings"

	"github.com/GoogleCloudPlatform/compute-image-tools/daisy"
)

// GetRegion extracts region from a zone
func GetRegion(zone string) (string, error) {
	if zone == "" {
		return "", daisy.Errf("zone is empty. Can't determine region")
	}
	zoneStrs := strings.Split(zone, "-")
	if len(zoneStrs) < 2 {
		return "", daisy.Errf("%v is not a valid zone", zone)
	}
	return strings.Join(zoneStrs[:len(zoneStrs)-1], "-"), nil
}
